Printing means



March 25, 1952 w. c. HUEBNER PRINTING MEANS Filed'June 25, "1945 3 Sheets-Sheet 1 INVENTOR Wi/z'am (ff/116511 ATTORNEYS March 25, 1952 w. c. HUEBNER 2,590,321

PRINTING MEANS Filed June 25, 1945 s Sheets-Sheet 2 Jig. 70.

INVENTOR B WWW,

ATTORNEYS March 25. 1952 w. c. HUEBNER 2,590,321

PRINTING MEANS Filed June 23, 1945 3 She ets-Sheet 3 i 7 v. jn avaarx wmq a, 2 a! VENTQR ATTORNEY Patented Mar. 25, 1952 UNITED STATES PATENT OFFICE 11 Claims.

This invention relates to improvements in printing means or apparatus and processes, and more particularly to improvements in printing .means and processes of the nature disclosed in my copending applications, Serial No. 593,449, filed May 12, 1945, now Patent No. 2,468,400, issued April 26, 1949, and Serial No. 595,818, filed May 25, 1945, in which is employed a printing element having a body of tubular cylindrical or other form which is of porous or permeable material or construction and provided with a printing surface composed of impervious, non-printing areas masking portions of said porous body, and pervious or open image-printing areas, whereby fluid inks, dyes or pigments can be caused to permeate or pass through the pores or interstices of the printin element for inking or applying the printing ink, dye or pigment to the printing areas of the printing surface for printing therefrom on paper, cloth, metal or other print-receiving materials. 1

Such porous or permeable printing elements are especially suitable for use in printing apparatus and processes, in which the transfer of the ink, dye or pigment from the printing surface to the print-receiving medium for making prints on the latter is effected without employing heavy pressure for causing printing contact between the printing element and print-receiving medium.

As an example of such apparatus and processes,

may be mentioned those in which the transfer of the ink or the like is effected by electric lines of force or electronic action, according to disclosures in U. S. patents issued to me, and in my pending patent applications, as distinguished from pressing the print-receiving medium into contact with the printing surface of the printing element under heavy pressure to lift the ink from the inked printing surface to the print-receiving material, as practiced in orthodox printing presses and processes.

Apparatus of the character mentioned ordinarily comprise means for producing electric discharges or electric lines of force in the restricted zone of printing where the print-receiving medium is brought into contact or closest contiguity with the printin surface, for the transfer of ink, dye or pigment from. the printing surface to the print-receiving medium. It has been found in. practice that it is desirable to precharge the ink, dye or pigment on the printing surface with an electrical charge of opposite polarity to that with which. the print-receiving material is charged before the ink, dye or pigment reaches the zone of printing where'it is transferred to the print-receiving medium by means of another electric charge or electric lines of force, in order thereby to increase the efficiency and thoroughness of transfer of the ink, dye or pigment to the print-receiving medium and improve the quality of the printing.

One object therefore of my invention is to provide a novel printing element having means for electrically precharging the ink, dye or pigment on the printing element prior to its transfer to the print-receiving medium to increase the ciliciency and completeness of transfer of the ink or the like from the printing element to the printreceiving medium.

Another object of the invention is to provide a novel porous or permeable printing element of the character mentioned having an electrically conductive meshwork or grid, associated with the printing surface thereof, through the interstices of which the ink, dye or pigment passes to the printin surface for electrically precharging the ink, dye or pigment by electric current carried by said mes'hwork or grid.

Other objects of the invention are to provide an efficient and desirable process and apparatus, including a porous or permeable printing element, means for causing fluid i r1 k, dye or pigment to pass through the acres or" interstices of the printing element to the'image-printing areas of the printing element for transfer to the printreceiving medium, and means for, electrically precharging the ink, dye or pigment passing to the printin surface of the element; also to provide a novel process of producing a printing element embodying a conductive meshwork or grid of the sort mentioned; and also to provide a novel process or means particularly suitable for producing printed work such, for example, as carbon tissue of that sort used for duplicating purposes in which different tissues have carbon coated and blank areas of different relative arrangements for use in duplicating different desired portions of an original subject.

Further objects and advantages of the invention willv appear from the following specification of the preferred embodiments of the invention shown in the accompanying drawings, and the novel features of the invention are set forth in the appended claims.

In said drawings:

Fig. 1 is a side elevational view, partly in lon- :itudinal section, illustrating a' printing element of tubular or hollow cylindrical form embodying my invention, together with its associated electrical contact devices.

Fig. 2 is an end elevational partly in section thereof.

Figs. 3-6 are fragmentary sections, on an enlarged scale, on the plane of line 33, Fig. l, illustrative of successive steps of the method described in the specification for providing the electrically conductive meshwork on the printing element.

Figs. '7 and 8 are similar views, illustrating successive steps of the described method of forming the printing surface on the periphery of the printing element.

Fig. 9 is a fragmentary face view of the finished printing element, the portions representing the printing surface and conductive meshwork in these Figs. '7, 8 and 9, being greatly exaggerated for clearness of illustration.

Figs. 10 and 11 are diagrammatic sectional views representing different types of printing apparatus embodying the invention.

Fig. 12 is a diagrammatic sectional view of means employed in producing a tubular printing element of modified construction embodying the invention.

Fig. 13 is a sectional view of the tubular element of said modified construction.

Fig. 14 is a sectional view of a non-tubular embodiment of the printing element.

The printing element I5 as illustrated in Figs.

1, 2, 8 and 9, comprises a tubular, hollow or cylindrical body N3 of suitable porous or permeable material through the pores of which the ink, dye or the like can permeate or pass in the manner of a filter and on the exterior periphery of which body is provided a printing surface which is composed of or comprises non-printing areas H which mask portions of the surface of the porous tubular body 16 and are impervious to the ink, dye or the like, and image-printing areas l8 which leave the registering surface portions of the porous body of the element expo'sed or are porous or otherwise provide exist for the ink, dye or the like from the body pores to the exterior of said image-printing areas to enable transfer of the ink, dye or the like from these areas to the print-receiving material or medium. This porous body of the printing element may consist of a cylindrical tube made of baked and unglazed clay, such as ordinary red clay, or suitable plastic or other material which is porous or permeable by fluid inks, dyes or pigments, as more fully disclosed in the above mentioned pending application.

Associated with the printing surface of said printing element and preferably surrounding the porous body 16 thereof is a fine meshwork or screen 19 of metal or other suitable electrically conductive material. The individual threads or bars of this meshwork or grid may be, for example, from one to two thousandths of an inch in width with the intervening spaces or interstices, for example, from two to six thousandths of an inch in width. This grid or meshwork as illustrated, is embedded in or lies beneath the exterior face of the non-printing areas I! of the printing surface and bridges or crosses the open or porous image-printing areas l8 so that the ink, dye or. pigment must pass through the interstices of said meshwork or grid in issuing from the body pores of the element to the exterior of said printing areas. The purpose of this mesh work or grid is to carry an electric current of a given polarity so that the ink, dye or the like passing through and contacting with the meshwork or grid will take therefrom an electric 4 charge of like polarity to assist in imparting to the particles of the printing ink, dye or pigment an electric charge of selected polarity, whereby during the act of printing, the ink, dye or the like which is transferred from the printing sur- [face to the print-receiving medium may be pre charged with a polarity opposite to that with which the print-receiving medium is charged, and thus insure a more complete transfer of the ink, dye or the like to the print-receiving medium. At its opposite ends, this meshwork or grid is formed with threads or bars 20 which extend circumferentially continuously around the printing element parallel with its end edges to provide continuous contact of the meshwork or grid with contact devices 2| when the printing element is revolving during its printing action, the contact devices 2| being connected with suitable conductors 22 for passing an electric current through the grid or meshwork from end to end thereof. Contacts 2| may be pivotally mounted to facilitate removal of the printing element.

Said conductive meshwork or grid can be provided on the printing element in any suitable way. A practical and desirable method for this purpose may be described as follows:

The surface of the porous body of the element is covered with a light sensitive solution which is dried to form a light sensitive surface coating, (indicated at 23 in Fig. 3) on the body. A transparent film (shown at 24, Fig. 3) on which black cross lines have been photographed or otherwise made to represent a fine meshwork or grid, is wrapped around the coated element body, and held in close uniform contact with the lightsensitive coating, and the latter is suitably ex-- posed to light through the film to light-harden the coating 23, except where the cross lines of the film protect the film from light.

After such exposure, the lined film 24 is removed and the light-sensitive coating of the element is developed, as under running water, and dried, whereupon the surface of the porous body will be freed of the coating where it was protected from light action by the black lines of the film, and these cleared away portions of the coating forming cross grooves (indicated at 25, Fig. 4) represent the cross lines of the transparent film. which has been removed. Suitable electrically conductive material, such as metallic graphite, which may be in the form of a paste or powder, is now applied or dusted over the surface of the coated porous body so as to occupy or fill said cross grooves 25 where the sensitive coating has been removed, to provide a base to accept an electrocleposit of copper, or other suitable metal which may be deposited on the body in said grooves by the well known electrolytic process, thus forming an electrically deposited metal grid or meshwork 19 on the porous element body, as illustrated in Fig. 5. The metal deposit need only approximate one thousandth of an inch in thickness, or it can be thicker if desired. After the metal grid or meshwork IQ of suitable thickness has been deposited on the body, the latter is removed from the electrolytic bath, washed clean, and the light-hardened portions (represented at 26 in Figs. 4 and 5) of the light-sensitive coating on the cylinder filling the spaces between the threads or bars of the meshwork or grid, are re moved by a suitable solvent, such as a caustic potash solution, and the body may be rinsed with water to which has been added a small proportion of suitable acid to neutralize any portion of the potash solution that may remain on the surface or in the pores of the body.

Thereafter, a lightsensitive solution is applied on the surface of the element body having the metal meshwork or grid on its periphery, and the solution dried to provide a light-sensitive peripheral coating (indicated at 21 in Fig. '7) on the body suitable for development to forrna photographic printing surface on the cylinder. Then by exposing this coating to light action through a suitable transparent film or medium (shown at 28 in Fig. 7 carrying an image representing the printing image to be formed on the printing element, and developing the exposed coating, as by washing with water, light-hardened portions of the coating will be left which form the impervious non-printing areas I! of the printing surface of the element. The remaining or image-printing areas of the printing surface, and which were protected from light action, will have been removed or rendered porous by the developing process, but these image-printing areas 18 will now have the metal grid or meshwork l9 exposed therein or bridging them, and the ink, dye or pigment in passing through the body pores of the printing element to these image-printing areas must pass through the interstices of this metal grid or meshwork.

In using the described printing element for making prints therefrom, the ink, dye or pigment may .be supplied to the interior of the tubular element and caused to pass or permeate through the pores of the element to the exterior of the image-printing areas of its printing surface in any suitable manner, for instance, as exemplified in the above mentioned copending application. The ink, dye or pigment, in being expelled through the body pores of the element to the exterior of said image-printing areas must pass through the metal grid or meshwork where it is exposed in said image-printing areas, and thus contact with the metal threads or bars thereof so as to become charged by the electric current supplied to the grid or meshwork, with the effect of augmenting the mobile properties of the ink, dye 01' pigment for transfer from the printing surface to the printing-receiving medium.

While, as above described and illustrated, the

printing element is of tubular or hollow cylindrical form for use as a rotary cylinder in a cylinder press, porous or permeable printing elements embodying the invention may be of other form. For example, Fig. 14 shows a printing element having a flat porous or permeable body provided with a printing surface similar to that described in connection with the tubular element. Ila indicates the impervious non-printing areas and [8a the image-printing areas which are of open, porous or other character, providing exit for the ink, dye or the like to the exterior thereof. The electrically conductive meshwork or grid, which is shown at l9a, may be provided in any suitable way, as by electro-deposition, as described in connection with the tubular element. In printing from an element of such form, the ink, dye or pigment may be applied to its under surface and caused to pass through the body pores thereof to the exterior of its image-printfrom current supplied to the meshwork or grid.

In the embodiment of the invention illustrated in Figs. 12 and 13, the porous or permeable tubulai' body of the printing element may be formed by a tubular meshwork, grid or screen 19b alone, without the provision of the porous clay or other tubular body I6 of the first described embodiment, said meshwork or screen itself constituting the porous tubular body of the element through the interstices of which the ink, dye or pigment is caused to pass the printing surface formed on the exterior of said meshwork or screen. 1 The printing surface comprising the impervious non-printing areas Ill) and the open or permeable image-printing areas I8b which provide exit for the ink, dye or pigment, may be formed by a method such as before described, by applying a light-sensitive coating exteriorly on the tubular meshwork, and photographically forming thereon the image to be printed by light action and development to provide the lighthardened, non-printing areas and the imageprinting areas where the light-sensitive coating was protected from light action and has been removed or made permeable by the developing process. In this embodiment of the invention, the meshowrk or screen 191) forming the porous tubular body of the printing element may be made of metal or other suitable electrically conductive material and may be constructed in any suitable manner. It could, for example, be pro;- duced by electrolytically depositing the metal meshwork or screen by the process before described and illustrated in Figs. 3-6, but in this case, depositing the meshwork on the periphery of a collapsible or removable cylindrical form, illustrated diagrammatically at 30 in Fig. 12, which form, after depositing the meshwork thereon, is removed, leaving the tubular mesh- Work or screen itself, to constitute the tubular body of the element, as illustrated in Fig. 13. This meshwork or screen body may be made heavier or thicker and stronger than that used on the porous body l6 of the element first described. This printing element may be used for printing in the same manner as explained in connection with the element first described, and the meshwork or screen charged by electric current for precharging the ink, dye or pigment passing through the interstices of the meshwork or screen to the image-printing areas [8b of the printing surface.

Fig. 10 illustrates diagrammatically a method of printing from a printing element of either the construction first described or that last described, in which the ink is transferred by electronic action or electric lines of force from the printing element to the print-receiving medium. In this Fig. 10, 15 represents the permeable printing cylinder, element 3|, the print-receiving medium which passes between the printing cylinder l5 and an opposing cylinder or roller which supports the print-receiving medium contiguous to or in contact with but without appreciable pressure against the printing cylinder. Within the printing cylinder [5 and the opposing roller or platen 32 are arranged suitable electrical elements or electrodes 33 and 34 of opposite polaritv for causing electronic discharges in the immeliate area of contact or contiguity of the print-receiving medium with the printingcylin -er for effecting the transfer of the ink from the printing cylinder to 'theprint receiving medium. The electric action of these elements 33, 34 is supplemented by precharging the ink on the printing surface of the printing element I 5 by means of an electric current supplied to the conductive meshwork l 9 of the element l5, as by the conductors 22 and contact devices 2|, as before explained. In addition, elements or electrodes 35 and 36 may be arranged to supply an electric charge to the print-receiving medium 3|, which charge will be of opposite polarity to that with which the ink is precharged by means of the meshwork 19 of the printing element.

Porous or permeable tubular or hollow cylindrical printing elements involving my invention are also desirable for use in printing apparatus or processes in which means other than electronic action or electric lines of force are employed for transferring the ink from the printing surface to the print-receiving medium. Fig. 11, for example, illustrates more or less diagrammatically such an apparatus in which the ink, dye orpigment is forced through the pores r interstices of the printin element and the image-printing areas of its printing surface by compressed air or other suitable gaseous medium. In this figure, l indicates the tubular porous or permeable printing element, which may be of either of the constructions hereinbefore described, to the inner surface of which the ink, dye or pigment is applied, for instance, by a suitable roll 40 which dips in the the ink, dye or pigment in a suitable receptacle 4|, suitably supported in the interior of the tubular element and rolls in contact with the inner surface of the element to apply the ink, dye or pigment uniformly over such inner surface of the element. Arranged within the printing element along the line of the printing zone where the print-receiving medium 42 is presented or held in contact or contiguity with the printing surface, as by a roller 43 between which and the printing element [5 the print-receiving web or medium travels, is a discharge tube or device 44 to which air or gas under pressure may be delivered, as through suitable conduits or connections 45, 46 of which the former may enter the printing element, as by a suitable swivel connection at one end at its axis of rotation. The discharge tube or device 44 has a narrow discharge slit 4'! which extends lengthwise close to the in ner surface of the printing element parallel with the line of tangential contact of the print-receiving medium with the printing surface, so that a narrow stream of air is blown from this slit through the pores or interstices of the printing element along the printing line or zone so as to blow the ink, dye or pigment which has been applied to the inner surface of the printing element, through the pores or interstices thereof and through the image-printing areas of the printing surface, as they pass this printing line or zone, onto the print-receiving medium, to thereby print or reproduce the image of the printing surface on the print-receiving medium.

I claim as my invention:

1. A continuous cylindrical printing element comprising a porous body which is permeable by fluid inks, dyes and the like and is provided with a printing surface including non-printing areas which are impervious to said fluids and leave printing areas which are porous and provide exit for said fluids from the pores of said body to the exterior of said printing areas, said printing element including electrically conductive material which bridges said printing areas of the printing surface and has minute interstices through which said fluids exit, means for electrically charging said conductive material, and an electrode of a polarity opposite to that of said conductive material and which charges the web to be printed, to cause printing fluid to be transferred by electric charges to said web.

2. A continuous cylindrical printing element comprising a porous body which is permeable by fluid inks, dyes and the like and is provided with a printing surface including non-printing areas which are impervious to said fluids and leave printing areas which provide exit for said fluids from the pores of said body to the exterior of said printing areas, and a flne meshwork of electrically conductive material which is incorporated in said printin surface and bridges said printing areas-thereof and has minute interstices through which said fluids exit, means for electrically charging said conductive material, and an electrode of a polarity opposite to that of said conductive material and which charges the web to be printed, to cause printing fluid to be transferred by electric charges to said web.

3. A printing apparatus comprising a continuous cylindrical printing element having a porous body which is permeable by printing fluid and is provided with a printing surface composed of non-printing areas which are impervious to said fluids, and image-printing areas which are pervious for exit of said fluids from the pores of said body to the exterior of said image-printing areas, said printing element including a layer of electrically conductive material which is in contact with said printing element and which bridges said image-printing areas of the printing surface beneath the exterior of said printing surface and has minute interstices for the exit of said fluid, means for passing an electric current through said conductive material for electrically charging said printing fluid prior to its transfer to the print-receiving medium, and an electrode of a polarity opposite to that of said material arranged in operative relation to a web to be printed to transfer electrical charges to said web.

4. A printing apparatus comprising a tubular printing element having a porous body which is permeable by printing fluids and is provided externally with a printing surface composed of non-printing areas which are impervious to said fluids, and image-printing areas which are porous for exit of the fluids from the pores of said body to the exterior of said image-printing areas, and an electrically conductive layer on which said printing surface is superimposed and which bridges said printing areas of the printing surface and has minute interstices for the exit of said fluids through which printing fluid may pass, means for imposing an electrical charge of one polarity on said peripheral layer, and an electrode of opposite polarity in operative relation to the web to be printed for transferring electrical charges thereto, to cause printin fluid to be deposited on said web by electrical charges.

5. A printing apparatus comprising a continuous cylindrical printing element having a porous body which is permeable by printing fluid and is provided with an exterior peripheral printing surface including non-printing areas which are impervious to said fluids and leave printing areas which are pervious for exit of said fluids from the pores of said body to the exterior of said printing areas, and an electrically conductive fine meshwork which is incorporated in said printing surface and bridges said printing areas thereof, and through which printing fluid may pass, means for imposing an electrical charge of one polarity on said meshwork, an electrode of said polarity arranged within said printing element and having its discharge end terminating at the portion of said cylindrical element which contacts with the web to be printed, and an electrode of opposite polarity in operative relation to the web to be printed for transferring electric charges thereto, to cause printing fluid to be deposited on said web by electrical charges.

6. A printing apparatus comprising a continuous cylindrical printing element having a porous body which is permeable by printing fluid and is provided with an exterior peripheral printing surface including non-printing areas which are impervious to said fluids and leave printing areas which are pervious for exit of said fluids from the pores of said body to the exterior of said printing areas, and an electrically conductive fine meshwork which is incorporated in said printing surface and bridges said printing areas thereof through which printing fluid may pass, a cylinder rotatable with its periphery in close proximity to said cylindrical printing element to support a web to be printed in close proximity to said printing element, means for imposing an electrical charge of one polarity on said meshwork, an electrode of the same polarity stationarily arranged within said printing element and having its discharge end terminating in close proximity to the inner surface of said cylindrical printing element which contacts with the web to be printed, an electrode of opposite polarity in operative relation to the web to be printed for transferring electrical charges to said web, and means for imposing on the surface of said cylinder an electrical charge of said opposite polarity, to cause printing fluid to be deposited on said web by electrical charges.

7. A printing apparatus according to claim 6 characterized in that the means for imposing electrical charges of opposite polarity on said cylinder comprise an electrode arranged in close proximity to the outer surface of said cylinder.

8. A printing apparatus according to claim 6, in which said means for imposing electrical charges of opposite polarity on said cylinder comprise a stationary electrode arranged within said cylinder and having the discharge end thereof arranged in close proximity to the portion of the cylinder which contacts with the web to be printed.

9. A printing apparatus according to claim 6, characterized in that said means for imposing said electrical charges of opposite polarity on said cylinder comprise a stationary electrode arranged within said cylinder and having the discharge end thereof arranged in close proximity to the portion of the cylinder which contacts with the web to be printed, and an electrode arranged in close proximity to the periphery of said cylinder for transferring similar electrical charges to the outer surface of said cylinder.

10. A printing apparatus including a printing element comprising a porous body which is permeable by printing fluid, a layer of electrically conductive material on the outer surface of said porous body and having minute interstices for the exit of said fluid, a printin surface on said layer having image printing areas which are pervious to said fluid and impervious non-printing areas, means for conducting an electric charge of one polarity to said layer of conductive material, from which layer said charge is transferred directly to said fluid passing through said interstices, and means for imposin an electric charge of opposite polarity to the web to be printed.

11. A printing apparatus including a printing element comprising a continuous unbroken tubular metallic member of fine meshwork having minute interstices permeable by printing fluid, and provided externally with a printing surface including areas which mask portions of said meshwork and are impervious to said fluid, and areas in which the interstices of said meshwork are exposed for the passage therethrough of said fluid to the exteriors of said areas, means for imposing an electric charge of one polarity on said metallic cylinder, and means for imposing an electric charge of opposite polarity on the web to be printed, for transferring said fluid through said last mentioned areas by electrical force.

WILLIAM C. HUEBNER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 729,045 Dick May 26, 1903 1,456,794 Gestetner May 29, 1923 1,541,787 Cadgene et al June 16, 1925 1,820,194 Huebner Aug. 25, 1931 2,049,495 Freuder Aug. 4, 1936 2,224,391 Huebner s Dec. 10, 1940 2,237,179 Gromm Apr. 1, 1941 2,239,619 Murgatroyd Apr. 22, 1941 2,267,901 Duncan Dec. 30, 1941 2,288,020 Noland June 30, 1942 2,408,144 Huebner Sept. 24, 1946 2,419,695 Shuttleworth Apr. 29, 1947 2,483,462 Huebner Oct. 4, 1949 FOREIGN PATENTS Number Country Date 375,168 Great Britain June 23, 1932 715,079 France Sept. 21,1931 

